Safety holder for walker die



March 19, 1957 c. H. MATHEWS 2,785,746

SAFETY HOLDER FOR WALKER DIE Filed Jan. 18, 1954 2 Sheets-Sheet l IN VEN TOR;

March 1957 c. H. MATHEWS I 2,785,746

SAFETY HOLDER FOR WALKER DIE 2 Sheets-Sheet 2 Filed Jan. 18,- 1954 villi/III!!!I lll'lll!"'I'IlIIII/IIIIII'IIIIIII SAFETY HOLDER FOR WALKER DIE Charles H. Mathews, Chicago, Ill.

Application January 18, 1954, Serial No. 404,756

Claims. (Cl. 164-29) The present invention relates to an improved holder for manipulating a punching or cutting die, commonly known as a walker die, beneath the reciprocating beam of an industrial press. The holder device eliminates a present source of danger to an attendant operating the die in the blanking out of rings, disks and like shapes from sheet material, which involves successive rapid movements of the die in a small vertical clearance space beneath the reciprocating head of the press and over the sheet to be punched.

The type of press in question, characterized as a beam press, has a massive, elongated horizontal beam which is reciprocated vertically at high frequency to and from a rigid base or platen. The die is successively manipulated from place to place along the length of the beam and over a sheet supported on the platen. Serious accidents resulting in the loss of an operators fingers occur frequently in this type of work, for it is not at all unusual for the operators finger to slip over the upper rim of the die, or under its lower cutting edge, and to be severed when the press beam descends to force the die through the material. if the die is slightly canted, as it is apt to be since it must be tipped to remove it from each cut hole, the die may be struck by the beam and be snapped sideways and down on the operators fingers or hand, usually with resultant injury.

Accordingly, the invention provides an improved safety holder or handle for use in operating a walker die, by which the hand of the operator is kept at all times out of the path of movement of the press beam. Full control of the die, in shifting the same lengthwise of the beam after successive cutting operations, is retained by the operator. The improvement relieves the operator of a considerable part of the weight of the die, substantially dereasing his fatigue after prolonged work at the press. I t also has the effect of improving the operators efficiency and output, to the extent that confidence in his personal safety unquestionably does. The likelihood of a decreased workmans compensation or liability insurance rate is another factor of appeal to an employer. Furthermore, a die can be replaced with no loss of time when a change-over is desired in respect to the particular shape to be cut.

To these ends a walker die is clamped in a ring shaped holder, being rigidly held therein by set screws, and the holder is mounted on the forward or outer end of an elongated, two-part telescoping support. This support consists of an elongated, universally swivelled rear tube in which a forward die supporting rod or tube is slidingly received for free telescoping movement. Thus the die may be successively positioned along the length of the beam of the press and may be drawn forwardly as desired to invert it and empt it of any accumulated stampings, or to replace one size or shape of die and ring holder with another.

The rear tube of the telescoped unit is preferably con nected by a universal, ball and socket or equivalent swivel connection to a suitable fixed support; thus. the die on ice the forward rod or tube thereof may be universally swung longitudinally and raised or lowered in punching shapes with maximum speed and economy. Moreover, in order to relieve the operator to a great extent of the burden involved in repeatedly lifting the relatively heavy die, a suitable counterbalance device is interposed between the rear swivelled tube and its fixed mount. The die holding ring and die may be completely removed from the unit for replacement by slipping the forward holding rod completely out of the pivoted rear tube. Die changeover time is reduced to a minimum. the operator to quickly invert the die and empty the same of cut parts accumulated in its hollow interior, if necessary.

As appears from the foregoing, it is a general object of the invention to provide a simple means for an operator to safely manipulate a walker die in relation to the reciprocating member of a beam press, in successively stamping out shapes from sheet material supported on a horizontal platen of the press, such means comprising a pair of telescoped rod members which can be easily assembled to any existing press.

The invention also has as a further objective the provision of a safety holder device, generally as outlined above, in which a secondary swivel or pivot between a die holder and its supporting rod enables a rectangular die to be operated with efficiency and economy by utilizing all of the space at the corners of a sheet being cut.

A. further adaptation of the invention contemplates the modification of a walker die itself to provide attaching means for a handle piece enabling the die to be slidably guided in the above described fashion as it is manipulated by an operator standing in front of a beam press. Such means may take the form of a threaded stud or bolt fixed on and projecting from one side of the die, to which a handle member can be conveniently and quickly applied by the operator, and preferably a similar element projecting from the opposite side of the die, to which the slidable guiding rod or tube may be similarly applied. A large number of dies may be so equipped with attaching elements and thus be interchanged rapidly by the operator in punching out different sorts of shapes, so as to entail a minimum loss of time in the change-over procedure. It is thus seen that the invention provides an improvement in a Walker die, per se, as a novel article of manufacture.

The foregoing statements are indicative in a general way of the nature of the invention. Other and more specific objects will be apparent to those skilled in the art upon a full understanding of the construction and operation of the safety device.

A single embodiment of principal features of the invention is presented herein for purpose of illustration. It will be appreciated that the invention may be incorporated in other modified forms coming equally within the scope of the appended claims.

In the drawings:

Fig. 1 is a fragmentary perspective view illustrating the improved safety holder for dies as operatively in stalled in relation to a well known type of beam press, indicating the manner in which the unit is manipulated by an operator in the successive punching of shapes from sheet stock;

Figs. 2 and 3 are, respectively, views partially broken away and in longitudinal horizontal and vertical section through the telescoped rod type safety holder;

Fig. 4 is a fragmentary top plan view showing. an adaptation of the holder for the handling of dies of noncircular shape;

Fig. 5 is a schematic top plan view showing. the way the unit of Fig. 4 is used in the punching of rectangular shapes;

This also enables- Fig. 6 is an elevational view of a holder incorporating a universal swivelling and balancing device different from that of Fig. l, the view being in vertical longitudinal section at the device; and

Figs. 7 and 8 are fragmentary views in side elevation illustrating further modified adaptations of the principle of the invention.

Referring to Fig. l, the reference numeral 10 generally designates a horizontally elongated beam of a vertically reciprocable press, which beam is vertically guided by the sliding reception of its upright side posts 12 in suitable ways (not shown) of the press base. The reference numeral 13 designates a piece of work to he died out, such as a sheet of synthetic rubber, leather or the like supported on a horizontal platen 14 of the press. A suitable compressible shim or spacer 15 is usually placed on platen 14 to support sheet 13.

The improved holder is generally designated 16. It is supported to the rear of thepress beam 10 on a rigid Wall or other upright surface 17 by means of an appropriate universal pivoting device 18. Figs. 1 and 2 depict this as a ball and socket coupling fixedly secured on surface 17. An elongated, forwardly extending hollow tube 19 of holder 16 is secured to an internal ball element 20 (Fig. 2 of this universal coupling, and a further elongated tube'or rod 21 of smaller diameter than tube 19 is telescopically received in the forward end of the latter.

There is a substantial length of overlap of the rods, as shown in Fig. 2 permitting a relatively long sliding travel of rod 21 in tube 19, and of a ring-type holder 22 which is fixedly secured on rod 21. Die holder 22 has radially extending set screws 23 which engage and clamp atubular blanking die 24 in fixed relation to rod 21. A forwardly extending hand piece 25 is secured to holder 22 in axial alignment with the rod 21 and tube 19. Die 24 may be of any appropriate type to stamp out the desired shape from sheet 13, being hollow in character, in the case of an annular shape. The die 24 is, per se, entirely conventional. That shown is adapted to the blanking of rings; it might also be a disk blanking type.

As shown in Fig. l, a spring counterbalance device 26 is employed to partially sustain the weight of unit 16. It is secured to tube 19 of the unit by a suitable adjustable clamping bracket 27, on which a forward rod of counterbalance 26 is pivoted; and the opposite end of the counterbalance is pivotally connected in any appropriate way on upright surface 17, at 28, preferably permitting universal movement at this point.

As press beam 10 reciprocates at a frequency of, say

70 or 80 strokes a minute the operator grasps handle piece 25 and, commencing at a forward corner of the sheet 13, proceeds to walk the die holder across the front end of the sheet, successively positioning the die 24 at spaced centers with its axis at 90 to the sheet. He does this by swinging the entire unit 16 about its pivot at swivel 18 and at the same time drawing rod 21 outwardly or pushing it inwardly relative to tube 19, as necessary to preserve a straight line of walk across the sheet, as indicated in Fig. 1. The press beam drives die 24 through the stock at each stroke, whereupon the operator frees the die from the punched work piece as the'beam retracts, shifts unit 16 sufficiently to afford material for the next blank, and continues this manipulation across the entire width of the sheet 13. Ring shapes 29 and blanked disks 30 will usually be stripped by internal die provisions (Figs.

2, 3) of conventional sort and drop onto a table surface upon forward shifting of the sheet manually over the platen 14 and cushion shim 15 by the operator; as appears in Fig. 1, it is possible to obtain a large number of stampings from a sheet in a skilled manipulation of unit 16 by the operator.

The unit is extremely simple and easily constructed and operated. The operators fingers and hands are at all times kept out of the range of operation of press beam 16, and the device relieves the operator of a tiring load which, in the absence of counterbalance 26 would be objectionable. Should occasion arise for the die changeover, this can be done quickly and simply by removing rod 21, holder 22 and die 24 as a unit from tube 19 and substituting another die and holder subassembly.

It is evident that the improved unit 16 may be used in various sorts of presses and other equipment other than a beam press in which the Walking manipulation of a die or similar tool is involved, usually with attendant danger.

Figs. 4 and 5 show a modified adaptation of unit 16 for use in the making of non-circular shapes, such for example as involve the use of a rectangular die 33. A rectangular holder 34 is employed in this case, having the hand piece 25 secured to one end thereof and being connected at its opposite end to sliding rod 21 by means of a horizontal pivot 35. Set screws. 36 clamp the die 7 33, in the same way as a holder for a circular die.

Fig. 5 shows how the rectangular die holder is swung about its secondary hinge 35 in order to square die 33 with the corners of a sheet 13 and thus use up all the material available at the corners. This would be impossible if the die were, of necessity, disposed at an angle to the sheet margins in many of the press strokes attending its walking along the length of press beam 10. Yet the ease and speed of manipulating the die are in no wise diminished by the provision of an additional, secondary pivot in the horizontal plane.

A modified and simplified swivelling and counterbalancing device 37 for the safety holder unit is shown in Fig. 6. A suitable casting or equivalent mount 38 is employed, which is characterized by parallel upstanding side plates 39, a top connecting bridge strap 40, and a rear hinge tongue 41.

Tongue 41 is horizontally swivelled to a fixed support bracket 42 by a vertical pin 43, and a horizontal pin 44 extending between and secured to side plates 39 serves as a pivot for a rear portion of tube 19 of device or unit 16. The tail extremity 45 of tube 19 is acted on by a coiled counterbalance spring 46, which is sustained from above by bridge strap 40. The spring is centered by a fixed depending pin 47 on the bridge and bears downwardly on tube 19 to urge the same clockwise about its pivot pin 44. Thus the weight of the die 24 and holder 22 are absorbed by a counterbalancing and swivelling unit which is extremely simple and rugged. The same unit is of course suited for use with the rectangular die provisions of Fig. 4.

The foregoing adaptations of the principle of the invention contemplate the alteration of a holder for a walker die by providing a handle piece 25 and an opposed slidable rod or tube element 21. Structural details of the die, per se, form no part of the invention, so embodied, and hence the die is only conventionally shown.

However, the principle of the invention may equally well be applied to the walker die itself. Thus, as illustrated in Fig. 7, a die 24 may be provided with opposed, outwardly projecting attaching elements, illustrated as threaded studs or bolts 32, 33' which are fixedly applied directly to the opposite sides of the die, as by welding. The handle piece or red 25 is appropriately tapped at 34 to be threaded on stud 32, and a lock nut 35' is employed to tighten the parts in assembled relation. Similarly, the

. rearwardly projecting guide tube 21 may have its forward end threaded at 36' to receive the rear stud 33", these parts also being held by a lock nut.

A still further modification of the same idea is illustrated in Fig. 8, for use in connection with a rectangular die. In this instance, only the guide rod 21 is shown. Rod 21 has a swivel connection, generally designated 37, to an adapter 38 which is internally threaded at 39. This adapter will fit on an attaching stud on a walker die which is modified as shown in Fig. 7, thus making the principle illustrated in that figure available for the type of punching operation depicted in Fig. 5.

I claim:

1. A safety die operating unit comprising a pair of members telescoped together for relative longitudinal movement, a swivel member on a rearmost member thereof acting to universally pivot the same on a support, a die holder mounted on the other, forwardmost member to support a die for engagement by an operating press with its cutting edge facing downwardly of the holder and of said telescoped members, and a hand piece on said last named member forwardly of said die holder enabling said die holder to be manually swung from a point in advance of said die holder about said universal swivel member as an axis.

2. A safety die operating unit comprising a pair of members telescoped together for relative longitudinal movement, supporting means on a rearmost member thereof providing universal movement of said pair relative to a fixed support, a die holder mounted on the other, forwardmost member to support a die for engagement by an operating press with its cutting edge facing downwardly of the holder and of said telescoped members, and a hand piece on said last named member forwardly of said die holder enabling said die holder to be manually swung from a point in advance, of said die holder relative to said fixed support.

3. A safety die operating unit comprising a pair of members telescoped together for relative longitudinal movement, a swivel member on a rearmost member thereof acting to universally pivot the same on a support, a die holder mounted on the other, forwardmost member to support a die for engagement by an operating press with its cutting edge facing downwardly of the holder and of said telescoped members, a hand piece on said last named member forwardly of said die holder enabling said die holder to be manually swung from a point in advance of said die holder about said universal swivel member as an axis, and a horizontal hinge connecting said die holder to said forwardmost member.

4. A safety die operating unit comprising a pair of members telescoped together for relative longitudinal movement, supporting means on a rearmost member thereof providing universal movement of said pair relative to a fixed support, a die holder mounted on the other, forwardmost member to support a die for engagement by an operating press with its cutting edge facing downwardly of the holder and of said telescoped members, a hand piece on said last named member forwardly of said die holder enabling said die holder to be manually swung from a point in advance of said die holder about said universal swivel members as an axis, and a counterbalance device acting on said rearmost member to at least partially sustain the weight of the unit.

5. A safety die operating unit comprising a pair of members telescoped together for relative longitudinal movement, supporting means on a rearmost member thereof providing universal movement of said pair relative to a fixed support, a die holder mounted on the other, forwardmost member to support a die for engagement by an operating press with its cutting edge facing downwardly of the holder and of said telescoped members, a hand piece on said last named member forwardly of said die holder enabling said die holder to be manually swung from a point in advance of said die holder relative to said fixed support, and a counterbalance device acting on said rearmost member to at least partially sustain the weight of the unit, said counterbalance device comprising a first element on which said rearmost member is pivoted to swing in one direction, an element pivoting said first named element on said fixed support to swing at to that direction, and a spring acting on said rearmost memher to urge said die holder upwardly.

6. A safety die operating unit comprising a pair of members telescoped together for relative longitudinal movement, a swivel member on a rearmost member thereof acting to universally pivot the same on a support, a die holder mounted on the other, forwardmost member to support a die for engagement by an operating press with its cutting edge facing downwardly of the holder and of said telescoped members, a hand piece on said last named member enabling said die holder to be manually swung from a point in advance of said die holder about said universal swivel member as an axis, a horizontal hinge connecting said die holder to said forwardmost member, and a counterbalance device acting on said rearmost member to at least partially sustain the weight of the unit.

7. A safety operating unit for a die or like member, comprising a pair of longitudinal, partially telescoped, forward and rear elements, universal means to pivot the rear element, a die member mounted on the forward element with a cutting edge of said member facing downwardly of said elements, and a hand piece on said forward element disposed forwardly of said member to enable said member to be swung about said universal meansfrom a point in advance of said member.

8. A safety operating unit for a die or like member, comprising a pair of longitudinal, partially telescoped, forward and rear elements, universal means to pivot the rear element adjacent the rear thereof on a support, a releasable holder for said member mounted on the forward element with a cutting edge of said member facing downwardly of said elements, and a hand piece on said forward element disposed forwardly of said holder to enable said holder to be swung relative to said support from a point in advance of said member.

9. A safety operating die unit comprising a die member adapted to be moved onto material to be operated on, attaching elements rigidly and permanently applied to opposite surfaces of said member to project outwardly of said surfaces in opposite directons relative to one another at approximate right angles to the direction of movement of said member toward said material, an elongated guide element, removably mounted on one of said attaching elements, a hand piece removably mounted on the other of said attaching elements, and a further element slidably receiving said guide element and allowing movement of the same transversely of said direction, said further element being universally connected to a support.

10. A unit in accordance with claim 9 in which said guide element comprises an elongated member having a pivotal attaching element thereon which is releasably engaged with an attaching element of said die member.

References Cited in the file of this patent UNITED STATES PATENTS 149,541 Stearns Apr. 7, 1874 989,059 Ryberg Apr. 11, 1911 1,284,784 Ryberg Nov. 12, 1918 1,362,365 Strong Dec. 14, 1920 1,633,755 Wolynski June 28, 1927 1,864,756 Pieper June 28, 1932 1,907,757 Drucket May 9, 1933 

